The water saver unit of the invention is a low cost water conservation device that can be installed on any toilet with a minimum amount of time and effort. The device is simple and will allow the installer to adjust the amount of water required to flush a toilet.
Most toilets can provide a full flush of solid and liquid waste by using slightly less than 2 gallons of water. However conventional toilets are designed to store and use from 3.5 to 7 gallons of water. The extra water is used to provide a hydraulic head pressure to start the flushing action. Once the flushing action has been initiated and approximately 2 gallons of water have been flushed into the toilet bowl, the water supply can be discontinued without any adverse effect on the toilet flush.
The conventional toilet tank design utilizes a flapper valve to retain the water in the toilet tank until a flush cycle is initiated. Once a flush cycle is initiated, the flapper valve will remain open until all or most of the water in the toilet tank is drained from the tank. The normal flapper valve contains an air pocket which keeps the flapper valve open until all of the water in the toilet tank is used in the flush cycle. At this time the flapper valve air pocket is released by the lack of water in the tank and the flapper valve closes to allow a refill of the toilet tank with water.
The flapper valve of the present invention is a unique design with no means for forming an air pocket, so that the flapper valve can be closed at the proper time. The new device takes advantage of the physics of the toilet design and closes the toilet flapper valve after approximately 2 gallons of water have been used, and is adjustable to allow the user to obtain optimum settings for the particular application. It should be noted that the device of the invention can be installed on any toilet by an unskilled person in a few minutes time. No tools are required. The existing toilet tank flapper valve is replaced with the new unit and the installation is complete.
The water saver unit includes a unique flapper valve that will close by its own weight and by the onrush of water from the toilet tank. This flapper closing action is neutralized by a submerged float which exerts a sufficient bouyancy force to keep the flapper valve open. When a flush cycle is initiated the flapper valve is lifted from its seat as it normally operates during a toilet flush. However once the water level drops to a predetermined level the float will no longer support the weight and water onrush forces on the flapper valve. The weight and water effects will act on the flapper valve, closing the flapper valve and halting the flow of water into the toilet bowl. The toilet tank will then refill with water in the conventional manner, awaiting the next toilet flush.
FIGS. 1-4 illustrate a typical prior art toilet tank 11. In FIG. 1, the conventional toilet components are in the normal position prior to initiation of a flush cycle. When the handle 12 is turned to initiate a toilet flush, the metal or plastic chain 13 connected to the flapper valve 14 lifts the flapper valve to its upright position as shown in FIG. 2. The flapper valve has a built-in delay device such as an air pocket or a metered water flow restrictor within the valve, whereby the flapper valve stays in the open position due to the bouyancy effect of the delay device. The water level 15 drops as the water in the tank 11 empties into the toilet bowl through the outlet opening 25, to provide the toilet flushing action. See FIG. 3. When the water is emptied from the toilet tank the flapper valve 14 closes by the gravity effect of the weight of the flapper valve and the absence of the bouyancy effect of the delay device. See FIG. 4. The in-flow control device 16 starts filling the toilet tank with water as soon as the water level 15 in the toilet tank drops below a predetermined level, as determined by the float 17. With the flapper valve closed the water from the in-flow control device 16 will fill the toilet tank until the float 17 rises to a level that closes the flow control device 16. The toilet is then ready for the next flush cycle. During the flush cycle all of the water in the toilet tank above the level of the flapper valve 14 is emptied into the toilet bowl via the drain opening 25.
During the flush cycle while the water in the toilet tank 11 is draining from the toilet tank into the toilet bowl, the flapper valve 14 is retained in the raised position by the bouyancy of the delay device and is independent of the handle 12 position as shown in FIG. 3.
After the water has been drained from the tank 11, the flapper valve 14 is in the closed position, allowing water to refill the tank through the flow control device 16. The flapper valve 14 closes by its own weight after the water is drained from the tank.
A number of newer designs have been proposed to improve the flushing operation and use less water. U.S. Pat. No. 3,969,775 in FIG. 2 shows a hollow flapper valve with an upper quick flood opening for in-flow of water and a lower drain opening for out-flow of water during the flush and fill cycle. A simple flat flapper is shown in FIG. 4.
This hollow float flapper design utilizes both a toilet flapper device with a built-in time delay (the air pocket in the flapper valve) and a separate float or bouyancy device to close the flapper valve when the float device is below the water level. The flapper design of this device is similar to all flapper delay devices on the market, relying on a hollow flapper which is more expensive to produce and which is precariously balanced with a bouyancy device, resulting in an unstable situation which is affected by toilet bowl design and is marginal in performance.
FIGS. 9 and 10 of U.S. Pat. No. 4,922,556 show a flapper valve without setting out any details of construction, other than stating that in FIG. 9 the flapper is floating and in FIG. 10 the flapper is non-floating.
A design presently being offered for sale under the name Flush-N-Save uses a bouyant float made from a soft flexible foam similar to that shown in U.S. Pat. No. 3,969,775.
The hollow flapper design is more expensive to produce and has problems with clogging of openings and limited life. In many types of toilets the device simply does not work. The air pocket under the flapper valve tends to hold up the valve until the entire amount of water has drained from the tank. The weight effect of the flapper valve and the bouyancy effect of the float must be designed to equalize each other and be placed completely above the flapper valve to allow it to close at a previously set position. The flat edge valve designs provide a flat seal surface, typically 0.100 to 0.125 inches thick, which surface is unsupported. Such flat surface tends to warp and leak due to the constant pressure of the water in the tank, requiring more frequent flapper valve replacement.
Another problem encountered with the prior art flapper design is the inconsistency in the seating and sealing at the outlet drain opening. This is particularly a problem with the flat type flappers which do not have a portion projecting downwardly for entering into the outlet opening and centering the flapper on the outlet opening. The flapper is connected to the overflow pipe by slender arms which permit lateral movement of the flapper relative to the outlet opening, so that accurate seating of the flapper on the outlet opening is not always achieved, resulting in leakage and waste of water.